The White House is commending Iraq's incumbent prime minister for stepping aside.
President Barack Obama's national security adviser is expressing hope that the power shift "can set Iraq on a new path and unite its people" against a security threat from Islamic State militants.
Susan Rice also says the United States remains committed to a strong partnership with Iraq and its people.
After initially struggling to stay in power, Nouri al-Maliki relinquished his post late Thursday to fellow Dawa Party member, Haider al-Abadi.
Rice's comments came in a statement issued while she was accompanying Obama on his Martha's Vineyard vacation.
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